This invention relates to an improvement of a Keplerian telescope type eye level finder in a single lens reflex camera (hereinafter referred to merely as "a camera" when applicable as disclosed in the specification of the prior Japanese Patent Application No. 21717/1977 filed by the present applicant.
In general, the finder of a camera is constructed so that an electing image is observed at eye level. However, in low angle, closeup and duplicating shots, a so-called waist level finder is more convenient. Accordingly, a variety of methods of alternately using the eye level finder and the waist level finder for one camera have been proposed in this art. For instance, for the most ordinary cameras comprising a penta-prism and an eye piece, a method is employed in which the penta-prism is modified to be removable from the camera, and the photographer looks directly into the focussing screen from above. Alternatively, a method is employed in which an angle finder comprising a dach prism, a relay lens and an eye piece is provided behind the above-described eye piece.
However, the former method is disadvantageous in that the right and left of the image to be observed are opposite to those of the object. That is, a reverse image is formed. The latter method is also disadvantageous in that the angle finder is expensive.
The Keplerian telescope type eye level finder has been also modified in a manner such that, as in the above-described penta-prism, the mirror or the prism above the focussing screen is modified to be removable (or foldable), and the photographer can directly look at the focussing screen. (cf. Japanese Patent Application Publication No. 15987/1976). Alternatively, it is modified in such a manner that an angle finder similar to that described above is provided behind the eye piece. Accordingly, the Keplerian telescope type eye level finder suffers from the same difficulties as those described above.